1. Technical Field
The present invention relates to an electrophoretic particle, a method of manufacturing an electrophoretic particle, an electrophoresis dispersion liquid, an electrophoresis sheet, an electrophoresis device, and an electronic apparatus.
2. Related Art
In general, it is known that the fine particles are moved (migrate) in the liquid due to Coulomb force when an electrical field is operated in a dispersion system in which fine particles are dispersed in a liquid. This phenomenon is known as electrophoresis, and in recent years, electrophoresis display devices in which desired information (images) is displayed using electrophoresis have garnered attention as new display devices.
The electrophoresis display device has display memory properties in a state in which application of a voltage is stopped and wide viewing angle properties, and is capable of high contrast display with low power consumption.
Since electrophoresis display devices are non-light emitting display devices, electrophoresis display devices are better for the eyes compared to a light-emitting display device such as a cathode ray tube.
Such an electrophoresis display device provided with a dispersion in which the electrophoretic particles are dispersed in a solvent as an electrophoresis dispersion liquid arranged between a pair of substrates having electrodes is known.
In an electrophoresis dispersion liquid with this configuration, electrophoretic particles including particles with positive chargeability and particles with negative chargeability are used, and, accordingly, it is possible for desired information (images) to be displayed by applying a voltage between the pair of substrates (electrodes).
Particles provided with a coating layer 503 in which a polymer 533 is connected to a base material particle 502 are generally used as the electrophoretic particles 501 (refer to FIG. 10), and the electrophoretic particles 501 can be dispersed and charged in the electrophoresis dispersion liquid by using a configuration provided with such a coating layer 503 (polymer 533).
The electrophoretic particles with this configuration are manufactured as follows, for example, using atom transfer radical polymerization reaction (ATRP).
That is, after base material particles 502 are prepared, and a silane coupling agent 531 having a polymerization initiation group is bonded to the surface of the base material particles 502, electrophoretic particles 501 are manufactured through imparting characteristics such as dispersibility by providing a polymer 533 while forming a polymerization portion 532 at which a monomer is polymerized by living radical polymerization with the polymerization initiation group as an origin (for example, refer to JP-A-2013-156381).
Incidentally, regarding whether the electrophoretic particles 501 have positive chargeability or negative chargeability in the electrophoretic particles 501 with this configuration, because the base material particles 502 themselves have inherent chargeability it is possible for a desired chargeability to be imparted on the electrophoretic particles 501 by selecting, as appropriate, the type of base material particle 502.
However, in the electrophoresis display device, although it is necessary to control the charging amount of the electrophoretic particles 501 in order to set the migration speed of the electrophoretic particles 501 to a suitable speed, it is difficult to control the charging amount of the electrophoretic particles 501 to a suitable range by simply providing the polymer 533 on the base material particle 502.